The Avengers tells the story of Loki (Tom Hiddleston), the adopted brother of Thor, who steals the Tesseract, a powerful energy source. Nick Fury (Samuel L. Jackson), director of S.H.I.E.L.D., recruits the Avengers to stop Loki and his alien army from conquering Earth. The film balances action, humor, and character development, thanks to Whedon's direction and the cast's chemistry.